1. Field of the Invention.
The present invention relates to safety break-away devices for banner support arms which are used for supporting large decorative banners and which have safety mounting couplings which break-away under high wind loading to prevent damage to the supporting pole and also to continue to support the banner to keep it from falling and causing injury or damage.
2. Description of the Prior Art.
In the prior art, various break-away devices have been used, particularly for bases supporting poles or standards, wherein when an excessive load strikes a pole or more usually when a car will hit the pole, the base will break-away and minimize damage to the automobile or the occupants, but will, of course, many times completely destroy the pole as it falls. A device such as that is shown in U.S. Pat. No. 3,951,556, which has coupling members for the support bolts that have reduced diameter break-away sections. These bolts are at the base of the pole and when broken, the entire pole will topple.
Similar break-away bolts are shown in U.S. Pat. No. 3,521,413 where, again, the bolts are positioned at the base of the large light standard or pole and when broken will permit the standard to fall.
A safety rail break-away post is shown in U.S. Pat. No. 3,499,630, and here again the break-away device is adjacent to the ground and all of the supported structure can tip over or topple when the break-away device fails. A connector of the same general type is shown in U.S. Pat. No. 3,349,531, and is envisioned for use in parking signs, parking meters and street name markers. The break-away connections are primarily for providing a release when the post is struck by an automobile.
A ceiling hanger that has reduced sections on a support rod so that the support rod length can be adjusted relatively easily is shown in U.S. Pat. No. 2,376,279.
Another patent which shows a break-away coupling, again for the base of a light pole or standard, but of slightly different construction which permits the mounting bolts to break out sections of threaded supporting sleeves that receive the bolts is shown in U.S. Pat. No. 4,007,564. These safety devices also are at the base of a pole or standard so that the roadway pole will fall when it is struck by an automobile.
Large banners are widely used by municipalities and shopping centers by shopping area merchants and others in order to advertise the area, attract shoppers, welcome visitors, or simply as decorative devices. The large cloth banners provide a substantial wind load stress on the supporting poles, and during gusts of high winds the added wind load stress can prove to be several times greater than the normal stress on the support pole, and such loads can cause the pole to fail at the base and crash to the ground. Limited success at preventing damage has been achieved by providing large holes in the banner so that the air can spill through the holes. While partially effective, the holes spoil the appearance of the banner. Some banners are made with a rigid supporting arm at the top with one or more small ropes that are attached loosely to a loose bottom arm. This arrangement allows the banner to flap in the breeze to spill off the excess air. The idea is that the ropes could be cut and released in the event of a sudden high wind, to save the poles from being destroyed. The arrangement is not very successful, and the constant flapping of the banner makes it annoying and destroys its aesthetic appeal.